CEP-1 Hormonal Regulation of Circulating Endothelial Progenitor Cells and HDL-C in Men (CEP-1)

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ClinicalTrials.gov Identifier: NCT00729859

Recruitment Status
:
Completed

First Posted
: August 8, 2008

Results First Posted
: October 12, 2012

Last Update Posted
: October 12, 2012

Sponsor:

University of Washington

Collaborator:

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

The original purpose of this research study was to understand the effects of testosterone (T) and estrogen on stem cells in the blood. The knowledge would be used to help understand the effects of T and estrogen on cardiovascular (heart and blood vessel) disease, and to help in the development of a safe male hormonal contraceptive.

The effect of androgens on the number of circulating endothelial progenitor (CEP) cells would best be observed in group 1 (placebo). Upon observation of group 1 under original protocol, changes in CEP cells were not significant but there were changes in markers of inflammation, lipids, and HDL protein composition. A modification to the protocol and title were made to reflect this for groups 2 and 3: Hormonal regulation of HDL-C in Men.

We will be administering three drugs: testosterone gel (T), anastrozole, and acyline. We want to see their effects on stem cells and hormone levels in the blood. Acyline suppress luteinizing hormone(LH) and follicle-stimulating hormone(FSH), which are hormones made by the pituitary gland, thus blocking the signal from the brain that causes the testes to make testosterone. Therefore acyline blocks testosterone production. Some men may experience side effects such as hot flashes or irritability from the low levels of T caused by acyline. We are studying whether adding T to acyline will reduce or eliminate these side effects.

Since heart disease is a common problem in men we want to know about the effects of male hormonal contraception on the cardiovascular system. One way to evaluate these risks is to measure the number of progenitor cells and the types of cholesterol in the blood. Progenitor cells are cells that travel in the blood and go to areas of blood vessel injury to help repair the damage amd may help prevent heart attacks and stokes. Some studies suggest that T administration may increase the number of these cells in the blood but other studies have shown that estrogen may be responsible for this effect. In addition, T and estrogen may affect the amount and type of HDL cholesterol in the blood. This is the "good" cholesterol that is thought to protect people from heart attacks and strokes. Therefore, more studies to test the effects of T and estrogen on progenitor cells in the blood and to understand HDL cholesterol in men receiving testosterone are needed.

Acyline is an experimental drug. The FDA allows its use only in research with a small number of volunteers. So far, over 125 men have received acyline. Anastrozole is a drug that blocks the production of estrogen from testosterone. Anastrozole has been given to men safely in the past. Anastrozole is not approved for use in men and is also an experimental drug. Testosterone gel will also be used in this study. It is FDA approved for use in men with low testosterone levels.

QUICKI is a measure of insulin sensitivity calculated using fasting insulin and glucose concentration in a participants blood. Higher QUICKI are associated with decreased insulin resistance and increased insulin sensitivity.

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Ages Eligible for Study:

18 Years to 55 Years (Adult)

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

Criteria

Inclusion Criteria:

Males age 18-55 years

Normal serum total testosterone (300 ng/dl-1000 ng/dl)

Normal LH and FSH levels

Taking no regular medications

Normal baseline serum hematology, chemistry and liver function tests

Agrees not to donate blood during the study

Agrees to use a form of contraception during the study

Subject must be able to comply with all study procedures

Exclusion Criteria:

Clinically significant screening assessments or other relevant disease, allergy or surgery, as revealed by history, physical examination and/or laboratory assessments, which may limit participation or prevent completion of the study

History of prostate cancer, breast cancer, or benign prostatic hypertrophy

Prostate-specific antigen (PSA) > 3.0

History of regular, chronic testosterone or anabolic steroid use in the past year

Chronic medical illness, prostate disease, or cardiovascular disease

History of a bleeding disorder or need for anticoagulation

Skin condition that might interfere with or be exacerbated by T gel use